An image forming apparatus includes an image forming unit which accommodates an image forming module for forming an image on a recording sheet supplied, and a sheet supply unit disposed in parallel with the image forming unit, having one or plural sheet supply trays and feeding recording sheets stocked in the sheet supply trays to the image forming unit side. Sheet feeding paths from at least some of the sheet supply trays to the image forming unit are constructed as a bypass feeding path extending from the farther sides of the trays from the image forming unit, and a cover which is opened or closed and disposed to face the bypass feeding path is provided to the farther side of a unit case, accommodating the trays, from the image forming unit.